Filtering apparatus and method for washing its filtering elements

ABSTRACT

A filtering apparatus and method comprises parallel filtering elements backflushable with the pressure of the filtered flow. At least one washing organ connecting alternately to the different filtering elements, forms a discharge channel for the washing flow. A freewheel clutch is connected to a rotating axle of the washing organ, converting reciprocating movement generated with the pressure of flow in the filtering apparatus and with pressure alternating with it into a continuously parallel, stepping rotary movement of the washing organ. The mechanism containing the clutch may be outside the filtering room of the apparatus, and based on the alternation of the higher pressure of the flow filtered in the apparatus and the lower pressure from the discharge channel. The freewheel clutch is articulated to a piston in the cylinder, and is moved back and forth with the pressure difference, controlled by the channels relaying the pressure and by the valves.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] This application is a continuation of copending InternationalApplication No. PCT/FI00/00800, filed Sep. 20, 2000, which designatedthe United States, and claims priority to Finish Patent Application19991997, filed Sep. 20, 1999, the disclosures of which are incorporatedherein by reference.

FIELD OF THE INVENTION

[0002] The invention relates to a filtering apparatus, comprising aninlet channel for the flow to be filtered, an outlet channel for thefiltered flow, a number of parallel filtering elements, into which theflow to be filtered may be directed so that the infiltration occurs outof the element through the element jacket, and at least one rotatingwashing organ connecting alternately to different elements for formingan outlet channel for the backflushing of elements generated with thepressure of the filtered flow. Further, the invention relates to amethod for washing the filtering elements of the apparatus.

BACKGROUND OF THE INVENTION

[0003] A filtering device is needed especially in motors as a fuel orluboil filter, with the continuous backflushing of which the operationof the motor is ensured in long-term continuous use. The apparatustypically comprises a large number of filtering elements, the main partof which is continuously in operation while the washing is conducted inone or several elements at a time, depending on the number of washingarms.

[0004] A state-of-the art backflushable filtering apparatus has beendescribed in the patent publication DE-4 340 275. The apparatuscomprises parallel, candle-shaped filtering elements arranged around avertical axle as two nested rings. The flow to be filtered is directedinto the elements from their upper and lower ends, and the infiltrationoccurs out of the element through the cylindrical jacket of eachelement. For backwashing the elements, a washing organ consisting of twowashing arms of different lengths is arranged below them, the arms beingfastened to the rotatable vertical axle of the apparatus. The washingarms are arranged to alternately connect to the lower ends of differentfiltering elements so that they form outlet channels for the washingflow. Corresponding to the washing arms, closers are attached to therotating axle of the apparatus above the filtering elements, the closersclosing the upper end of the filtering element in question for theduration of the washing stage, thus preventing the flow to be filteredfrom mixing with the washing flow.

[0005] According to the publication DE-4 340 275, the rotating movementof the vertical axle of the apparatus and the washing arms is achievedwith the help of a turbine rotor arranged in the inlet channel of theflow to be filtered and with cogwheels connected to it and acting as atransmission mechanism. The movement of the washing arms is thusmaintained by the motion energy of the flow coming into the apparatus.

[0006] The drawback of the solution in the publication DE-4 340 275 isthat the rotation of the washing arms is dependent on the flow rate ofthe flow to be filtered coming into the apparatus, which may vary. Ifthe flow rate is too high, it makes the washing arms to rotate too fast,and the washing periods of the filtering elements remain too short; andagain, if the flow rate is too low, the washing arms rotate too slowlyfrom one element to the other, or they stop altogether, if thedecelerated flow cannot rotate the turbine rotor any more. The rotationof the washing arms is hindered by the rotor and the transmissionmechanism getting dirty, and due to the structure of the apparatus, itis difficult to service the mechanism.

SUMMARY OF THE INVENTION

[0007] The object of the invention is to provide a solution, in whichthe axle of the apparatus and one or several washing organs are rotatedby utilising the flow pressure present in the apparatus so that thedrawbacks associated with the state-of-the art technology can beavoided. It is characteristic of the filtering apparatus of theinvention that a freewheel clutch is connected to the rotating axle ofthe washing organ, which converts the reciprocating motion generated bythe pressure of the flow present in the apparatus and by the lowerpressure alternating with it into a continuously parallel, steppingrotary motion of the washing organ.

[0008] According to the invention, the rotation of the washing organ andthe washing periods in different filtering elements are generated with apressure difference, which it is possible to keep substantiallyconstant, or which varies less than the flow rate of the flow cominginto the apparatus. This ensures that the sufficiently long washingperiods are repeated with a suitable frequency in all filtering elementsof the apparatus.

[0009] A substantial advantage of a second solution of the invention isthat the freewheel clutch may be arranged outside the filtering room ofthe apparatus, connected to the rotating axle, so that it is easy toservice the freewheel clutch and other organs maintaining the rotatingmovement, and the service may be carried out while the filteringcontinues.

[0010] The freewheel clutch may consist of an actuator driving therotating axle of the washing organ, which is alternately in slidingcontact with the axle and which alternately locks into it so that theaxle rotates along with the organ. The movement of the actuator may begenerated, for example, by articulating it to a piston reciprocating onthe alternating pressure.

[0011] The pressure of the filtered flow is especially advantageouslyused for rotating the washing organ, by arranging the said flow toinfluence the said piston or another organ driving the freewheel clutch.The filtered flow is pure, so that it contaminates the rotatingmechanism substantially less than an unfiltered flow. The apparatus ofthe invention preferably comprises channels and related control valvesfor connecting the pressure of the filtered flow and the lowercounterpressure alternately to different sides of the piston.

[0012] The lower pressure opposite the said pressure of the filteredflow may be the pressure prevailing in the outlet channel for thewashing flow of the apparatus, to which the piston or another actuatormay be connected. In the filters of a motor, the outlet channel isgenerally in the atmospheric pressure prevailing in the surroundings.

[0013] The solution of the invention makes it possible to hydraulicallyadjust the rotating movement of the washing organ so that the frequencyand duration of the washing periods may be controlled with it. Themovement of the washing organ may thus be damped, or it may be stoppedexactly at the place of the element to be washed, in which the washingorgan remains for a desired time before the movement continues.

[0014] In the method of the invention, the filtering elements are washedin the filtering apparatus, comprising an inlet channel for the flow tobe filtered, an outlet channel for the filtered flow, and a number ofparallel filtering elements, into which the flow to be filtered isdirected so that the infiltration occurs out of the element through theelement jacket. The washing is achieved by coupling alternatelydifferent filtering elements to the rotary washing organ so that thewashing occurs as backflushing directed to the washing organ with thepressure of the filtered flow. Essential in the method is that therotating axle of the washing organ is rotated continuously in the samedirection in a stepping manner using a mechanism, the reciprocatingmovement of which is generated with the pressure of the flow in theapparatus and with the lower pressure alternating with this. The formerpressure is advantageously the pressure of the clean flow filtered inthe apparatus, and the lower pressure is the ambient pressure present inthe washing arm.

[0015] In the method, the steps of the washing organ may be generatedwith a freewheel clutch, comprising an organ driving the rotating axleof the washing organ, which is alternately in sliding contact with theaxle and which alternately locks into it for rotating the axle, the saidorgan being moved with a piston articulated with it, the piston beingreciprocated by coupling the said pressures of different sizesalternately to its different sides.

BRIEF DESCRIPTION OF THE DRAWINGS

[0016]FIG. 1 is a vertical section of a filtering apparatus of theinvention;

[0017]FIG. 2 is a horizontal section II-II of FIG. 1, in which theparallel filtering elements of the apparatus and the washing organsabove them are shown;

[0018]FIG. 3 shows the freewheel clutch and control valves connected toit for rotating the axle of the apparatus in the one extreme position ofthe coupling movement, as a section III-III of FIG. 1;

[0019]FIG. 4 is a similar view to FIG. 3, presenting the freewheelclutch in its other extreme position;

[0020]FIG. 5 shows the freewheel clutch of a second embodiment of theinvention, with the related control valve, the coupling movement beingin the other extreme position;

[0021]FIG. 6 shows the freewheel clutch of FIG. 5 in the middle positionbetween the extreme positions of its movement; and

[0022]FIG. 7 is a vertical section of the coupling apparatus of FIGS. 5and 6.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT

[0023] In FIGS. 1 and 2, there is shown a filtering apparatus, which maywork, for example, as the luboil filter of a diesel motor, continuouslyfiltering oil as the motor is running. The apparatus comprises a jacket1, an inlet channel 2 for the flow to be filtered, an outlet channel 3for the filtered flow, and a number of longitudinal, candle-shapedfiltering elements 5 arranged as two nested rings around the middle axis4 of the apparatus. The jackets of the elements 5 are made of porousfiltering material, which retains the solid particles or otherimpurities in the flow as the flow extends from the interior of theelements through the jacket and out of the elements. For directing theflow to be filtered into the elements 5, each element is open both fromits upper end 6 and lower end 7. The spaces between the ends 6, 7 ofadjacent filtering elements are closed with a horizontal plate 8, 9 bothat the lower and the upper end of the elements. The plates 8, 9 arefurther connected to each other with a vertical, cylindrical wall 10,which confines in its interior a vertical flow channel 11 for the flowto be filtered. Thus, the flow can spread into the space restricted bythe jacket 1, from where it is transferred into the elements through theopen ends 6, 7 of the filtering elements 5, extends through the elementjackets out of the elements and is discharged as purified into theoutlet channel 3.

[0024] In the apparatus according to FIG. 1, each of the candle-shapedfiltering elements 5 is divided in two by a horizontal, solid partition12. Each element 5 thus comprises an upper part 13 open from its upperend and a lower part 14 open from its lower end, through which the flowsto be filtered travel independent from each other.

[0025] During the filtering process, the solid material gathering to theinner surfaces of the jackets of the filtering elements 5 graduallyblocks pores of the jacket, thus causing a decrease in the filteringcapacity. In order to maintain the operation of the elements, theapparatus is provided with backflushing, which is conducted with thepressure of the filtered flow in the direction opposite to the flow tobe filtered through the element jackets, i.e. from the outside of thejackets into them. Above and below the adjacent elements 5, washingorgans 15 connecting alternately to different ends 6, 7 of the elementsare arranged for coupling the elements to the lower pressure forgenerating the washing flow. Both washing organs consist of two washingarms 15, the lengths of which are equal to the radii of the nested ringsformed by the elements. The washing arms are made of a hollow tube, andthey are fastened to the likewise hollow middle axle 4 of the apparatusso that together they work as discharge channels 16 for the washing flowcleaning the element. The discharge channels 16 are directed to thelower part of the apparatus, from where the washing flow is suitablydischarged, for example, to the discharge assembly 18 in atmosphericpressure, after having passed through the filter 17.

[0026] In the apparatus described, the backflushing works so that theaxle 4 with the washing arms 15 fastened to it performs a rotatingmovement counter clockwise so that the washing arms connect from theirends alternately to the ends 6, 7 of different filtering elements 5,thus coupling the interiors of these elements to a pressure which islower than the pressure of the filtered flow in the discharge channels16 and the discharge assembly 18, thus generating the backflushing. Thewashing occurs in the part between the end of the element 5 and thepartition 12 at the same time as the opposite end of the element is openso that the filtering may continue in the part restricting to the saidopen end of the element. Thus, FIG. 1 presents a situation, in which thefiltering continues in the lower part 14 of the leftmost element, whilethe upper part 13 of the element experiences backflushing, and thefiltering continues in the upper part 13 of the rightmost element at thesame time as the lower part 14 of the element experiences backflushing.Further, the filtering is naturally in constant operation in thosefiltering elements, which are not connected to the washing arms 15.During the process, the lower and upper part of each filtering elementis cleaned by backflushing at regular intervals so that the filteringcapacity of the whole apparatus is kept substantially constant in theprocess.

[0027] The rotating movement of the construction consisting of the axle4 belonging to the apparatus and of the washing arms 15 rigidly attachedto the axle is generated with a mechanism, the structure and operationof which may be seen in FIGS. 3 and 4. The rotating mechanism isarranged into the casing 19 above the filtering space defined by thejacket 1 of the apparatus, the end 20 of the axle 4 of the apparatusextending into this casing. The axle 20 is driven by a freewheel clutch,which comprises an organ 21 annularly circulating the axle and moving ina reciprocating manner in accordance with FIGS. 3 and 4 so that it isalternately in sliding contact with the axle and that it alternatelylocks into the axle for rotating the axle along with the organ,depending on the direction of the movement. Such coupling arrangements,which may be based, for example, on an inclined, flexible or yieldingcogging, are known as such. The organ 21 thus slides from the positionaccording to FIG. 3 to the position according to FIG. 4 on the axle 20,which remains stationary, but as the organ returns back to the positionin FIG. 3, it locks into the axle rotating it along one step counterclockwise. Thus, the axle 20 steps counter clockwise, rotating thewashing arms 15 (FIGS. 1 and 2) so that they alternately connectdifferent filtering elements 5 to the washing stage.

[0028] The annular organ 21 circulating the axle 20 is provided with twoprotruding arms 22, 23 arranged opposite each other, the one arm 22being articulated to the piston 25 moving in the cylinder 24. The piston25 is moved in the cylinder 24 back and forth utilising the higherpressure of the filtered flow present in the filtering room of theapparatus and the lower pressure of the washing channels 16, byconnecting these to the cylinder alternately in different sides of thepiston. From the side of the filtered flow, the filtering room is incontact with the casing 19 containing the freewheel clutch through thechannel 26 (FIG. 1) so that the casing is filled with the filteredsubstance, such as lubricating oil. Respectively, a connection is builtfrom the casing 19 to the flushing channels 16 through the channel 27.The piston 25 is controlled with the main valve 28 and two controlvalves 29, 30 controlling it. The main valve 28 is connected to thecylinder 24 at different sides of the piston 25 driving the freewheelclutch using the tubes 31, 32. In the figures, the leftmost controlvalve 29 is connected to the front end of the main valve 28 with thetube 33, and the rightmost control valve 30 is connected to the back endof the main valve with the tube 34. Further, the main valve 28 and thecontrol valves 29, 30 are connected to the said channel 27 in the lowerpressure with the tubes 35, 36, 37, 38.

[0029] In the freewheel clutch position according to FIG. 3, the arm 23of the actuator 21 has pressed the piston 39 inside the leftmost controlvalve 29 against the spring into a position in which it releases thehigher pressure in the casing 19 from the assembly 40 into the tube 33and from there to the front end of the main valve 28, in which it haspushed the piston of the main valve to a position in which the pressurein the casing 19 has connected from the assembly 42 to the tube 31,which connects the pressure with the cylinder 24 to the right side ofthe piston 25 driving the freewheel clutch. At the same time, the backend of the main valve 28 is connected to the lower pressure in thechannel 27 through the tube 34, the right control valve 30 and the tube38. The movement of the piston 41 of the main valve 28 connects thecylinder 24 to the said lower pressure from the left side of the piston25 through the tube 32, the main valve and the tube 35.

[0030] Connecting the pressure in the casing 19 through the tube 31 tothe cylinder 24 at the right side of the piston 25 now makes the piston25 to move to the left in the figures so that the piston and the organ21 driving the axle 20 slide into the position in FIG. 4. In this case,the actuator arm 23 presses the right control organ 30, the structure ofwhich is the mirror image of the left control valve 29, against thespring of the inner piston 43 to a position, in which it connects thepressure in the casing 19 through the tube 34 to the back end of themain valve 28, in which the pressure moves the piston 41 so that thetube 32 in its turn connects to the higher pressure in the casing 19through the assembly 42, and the tube 31 is connected to the lowerpressure in the channel 27 through the main valve 28 and the tube 36. Atthe same time, the movement of the arm 23 has let the piston 39 of theleft control valve 29 to move to the right, pushed by the spring, sothat the movement of the piston 41 of the main valve 28 has been madepossible as the front end of the main valve has connected to the lowerpressure in the channel 27 through the tube 33, the left control valve29 and the tube 37.

[0031] Coupling the higher pressure in the casing 19 in the positionaccording to FIG. 4 to the left end of the cylinder 24 makes now thepiston 25 and with it also the actuator 21 and the axle 20 locking intoit to return counter clockwise into the position in FIG. 3 at the sametime as the movement of the piston 43 of the right control valve 30couples the back end of the main valve 28 to the lower pressure inchannel 27 for allowing the movement of the piston 41 of the main valve.The actuator arm 23 presses the piston 39 of the left control valve 29to a position, in which it couples the pressure in the casing 19 to thetube 33 leading to the front end of the main valve 28. Thus, therotating mechanism has returned to its initial position, after which itsoperation continues in the way that is described above.

[0032] The duration of the washing periods may be adjusted by stoppingthe washing arm 15 at the place of the element 5 to be washed for adesired period. The adjustment may be achieved, for example, with flowcontroller valves (not shown) installed into the tubes 31 and 32, whichslow down the reverse stroke of the piston 25 of the cylinder 24, sothat the arm 15 stays stationary during the movement in question.Alternative ways for adjusting the rotating movement of the arm 15 mayinclude the adjustment of the pressure prevailing in the casing bychoking the flow going into or out from the cylinder 24 in the channels26 and 27 with a valve or valves placed in the channel 26.

[0033] FIGS. 5-7 show an alternative control arrangement for thefreewheel clutch for rotating the axle 20 and the washing arms of thefiltering apparatus. For the part of the reciprocating coupling ring 21,piston cylinder 24, valve 28, and the tubes 31, 32 between the valve andthe piston cylinder, the flow assembly 27 leading into the washingchannels, and the tubes 35, 36 leading into it from the valve 28, thestructure in FIGS. 5-7 corresponds to that shown above in connection ofFIGS. 3 and 4, and therefore, they are not explained in more detailhere.

[0034] Compared with FIGS. 3 and 4, the substantial difference in FIGS.5-7 is that the valve 28, which corresponds to the main valve 28 inFIGS. 3 and 4, forms the only control valve of the system. In FIGS. 5-7,the control valves 29, 30 in FIGS. 3 and 4 are replaced with twoprotruding arms 44, 45 belonging to the rotating parts of the freewheelclutch, which along with the reciprocating rotating movement transferthe piston of the valve 28 back and forth between the two positions sothat the higher pressure in the washing channels and the flow assembly27 and the lower pressure in the casing 19 of the freewheel clutch,containing the valve 28, are alternately directed to different sides ofthe piston in the cylinder 24, maintaining thus the reciprocatingmovement of the ring 21 and the parallel stepping rotating movement ofthe axle 20. FIG. 5 shows the position of the ring 21 and the left arm44, in which the arm has pushed the piston of the valve 28 into theextreme right position of the piston. In FIG. 6, the piston of thecylinder 24 has rotated the ring 21 counter clockwise by pushing the arm22 to the half-way of the movement, in which the arms 44, 45 driving thevalve 28 are both detached from the ends of the valve. As the rotatingmovement continues further, the right arm 45 pushes the piston of thevalve 28 to the position extremely in the left, so that the pressures indifferent sides of the piston of the cylinder 24 switch places and startthe reverse stroke of the piston and the rotation of the ring 21clockwise back into the position according to FIG. 5.

[0035] The freewheel clutch controlled with the pressure difference hasthe problem that if the pressure difference is small and/or if there isfriction in the moving parts of the mechanism, it easily occurs that thepiston of the cylinder 24 begins to move but it does not have enoughstrength to complete the movement, but it stops without achieving therotation of the axle 20. It may also happen that the strength of the arm44, 45 is not sufficient to move the piston of the valve 28, which isthe condition for the continuance of operation of the apparatus. Theseproblems have been eliminated with the structure utilising magnets,which will be described next.

[0036] Besides the clutch ring 21 rotated by the arm 22 of the pistoncylinder 24 pivoted to the axle 20, the coupling comprises a separatecoupling ring 47 provided with the crank arm 46 of its own, which isalso pivoted to rotate the axle 20. The arms 44, 45 moving the piston ofthe valve 28 are attached to the latter ring 47. The rotation of the arm46 and the coupling ring 47 is achieved with the help of magnets in thearm installed stationarily in relation to the casing 19. The end 46 ofthe arm is provided with a magnet 48, which is attracted by the magnets49, 50 in FIGS. 5 and 6 installed stationarily to the ends of the path.Slightly in the direction of the coupling ring 47, the arm 46 comprisesa second magnet 51, with two repelling magnets 52, 53 placed above andbelow. The three magnets 51, 52, 53 mentioned last are situated oppositeeach other as the arm 46 is in the half-way of its movement according toFIG. 6.

[0037] In the initial position of the rotation of the coupling ring 21in FIG. 5, the attracting magnets 48 and 49 have a decelerating effectto the rotary movement. When transferring from the initial position inFIG. 5 to the position in FIG. 6, in which the rotation of the ring 21is half-way, the attractive force of the magnets 48 and 49 decreases asthe distance between them grows at the same time as the repelling forceof the magnets 51-53 increases as they move closer to each other. Theadded effect of the magnets thus resists the rotation of the ring 21.

[0038] The idea of operation of the rotating mechanism is, however, thatthe rotation performed by the piston of the cylinder 24 is limited onlyto the transfer of the arms 22 and 46 from the initial position in FIG.5 to the middle position of the movement in FIG. 6. At this stage, thearms 22 and 46 and the coupling rings 21 and 47 rotate together. In themiddle position of the movement, the effect of the magnets is labile,and as soon as the middle position of the movement has been passed, themagnets 51-53 repelling each other give a strong push forwards for themovement of the arm 46, the movement being further strengthened by theattracting magnets 48 and 50 coming closer to each other. In thisconnection the arm 46, which until now has moved along with the arm 22pushed by the piston of the cylinder 24, is able to move in front of thearm 22 pushed by the piston within the tolerance adjusted by the controlscrews 54 seen in FIGS. 5 and 6, and to finish the rotating movement byrotating the coupling ring 47. Thus, after its half-way, the rotatingmovement is no longer dependent on the pressure difference prevailing inthe piston cylinder 24, and the rotating movement accelerated towardsthe end by the magnets does not tend to remain unfinished, as couldhappen when operating merely on the pressure difference and the cylinderpiston.

[0039] The working mechanism of the freewheel clutch in FIGS. 5-7explained above is inventive in the opinion of the applicant, andbesides the stepping rotation of the axle of the washing organ in thefiltering apparatus, it may applied to any other application, in whichthe stepping rotary movement is controlled on the pressure difference.

[0040] It is obvious for one skilled in the art, that the variousembodiments of the invention are not limited to the ones shown asexamples above, but they may vary within the scope of the enclosedclaims. Especially the arrangement and detailed structure of thefiltering elements of the apparatus, which are not the primary object ofthe invention, may deviate from the ones shown in the drawings. Neitherdoes the invention require that washing organs be placed to both ends ofthe filtering elements, but if may also be sufficient to provide arotating washing organ to one end of the elements, to which each of thefiltering elements will be coupled in its turn.

[0041] In the mechanism shown in FIGS. 5-7, the attracting magnets 48-50or the repelling magnets 51-53 may by themselves be enough to achievethe effect intensifying the necessary rotary movement.

What is claimed is:
 1. A filtering apparatus, comprising an inletchannel for flow to be filtered, an outlet channel for filtered flow, anumber of parallel filtering elements , into which flow to be filteredmay be directed so that infiltration occurs through a jacket of anelement, and at least one rotating washing organ connecting alternatelyto the different elements for forming a discharge channel forbackflushing of the elements generated with the pressure of the filteredflow; and a freewheel clutch connected to a rotating axle of the washingorgan, wherein the clutch converts reciprocating movement generated withpressure of the flow in the apparatus and alternating lower pressureinto a continuously parallel, stepping rotary movement of the axle. 2.The apparatus according to claim 1, wherein the freewheel clutchcomprises a coupling organ driving the rotating axle of the washingorgan, which is alternately in sliding contact with the axle and whichalternately locks into the axle for rotating the axle, the said couplingorgan being articulated to the piston reciprocating on the alternatingpressure.
 3. The apparatus according to claim 2, wherein in theapparatus includes channels and related control valves for coupling thepressure of the filtered flow and the lower counterpressure alternatelyto different sides of the piston.
 4. The apparatus according to claim 3,wherein the pressure in the discharge channel of the backflushing flowis coupled as counterpressure for the pressure of the filtered flow. 5.The apparatus according to claim 1, wherein the filtering elements arecylindrical and arranged on one or several circumferences surroundingthe rotating axle of the washing organ.
 6. The apparatus according toclaim 5, wherein the washing organ consists of one or more tubularwashing arms transverse to the rotating axle and connecting alternatelyto the ends of different filtering elements
 7. The apparatus accordingto claim 1, wherein the apparatus includes two or more washing organsconnected to the same rotating axle for simultaneous backflushing of twoor more filtering elements.
 8. The apparatus according to claim 7,wherein the apparatus comprises a washing organ at both ends of theparallel filtering elements, and that the washing organs are made as onepiece with the rotating axle.
 9. The apparatus according to one claim 1,wherein the apparatus is adapted for filtering a fuel or luboil filterof a motor, especially a luboil filter of a diesel motor.
 10. A methodfor washing filtering elements in a filtering apparatus, which comprisesan inlet channel for flow to be filtered, an outlet channel for thefiltered flow, and a number of parallel filtering elements, into whichthe flow to be filtered is directed so that infiltration occurs throughan element jacket, in which method the washing is achieved by connectingdifferent elements alternately to a rotating washing organ so that thewashing is carried out as backflushing directed to the washing organwith the pressure of the filtered flow, and a rotating axle of thewashing organ is rotated in a stepping manner continuously in the samedirection using a reciprocating mechanism, the reciprocating movement ofwhich is generated with the pressure of the flow prevailing in theapparatus and alternating lower pressure.
 11. The method according toclaim 10, wherein the axle of the washing organ is rotated with thepressure of the filtered flow and with the lower pressure alternatingwith the filtered flow pressure.
 12. The method according to claim 10,wherein the steps of the washing organ are generated with a freewheelclutch, comprising a coupling organ driving the rotating axle of thewashing organ, the coupling organ being alternately in sliding contactwith the axle and alternately locking into the axle for rotating theaxle, the moving of the said coupling organ being carried out with apiston articulated with the coupling organ, the piston being moved backand forth by connecting the said pressures of different elementsalternately to different sides of the piston.